Hands-on approach to physics

Demonstrations make a difficult subject easier to understand.

Demonstrations make a difficult subject easier to understand.

November 13, 2006|ANNE KIBBLER The Herald-Times

BLOOMINGTON, Ind. -- Kristen Britton stood with her back against the classroom wall, the tip of her nose just millimeters from a 12-pound, dark red bowling ball suspended from the ceiling. As she stared straight ahead, Owen Valley High School physics teacher Jay Inman, having drawn the ball close to her face, let it go. The ball arced away, then swung back in a collision course with her head, stopping just short of disaster. Kristen wasn't buying it. "She flinched! She flinched!" Inman said. "Go and sit down, you who don't believe!" What Kristen was supposed to believe in was the law of conservation of gravity. According to that law, the bowling ball would reach its maximum velocity at the low point of its swing outward. On its return arc -- the seeming path of disaster for Kristen -- it would slow, then stop harmlessly before colliding with Kristen's nose, finally reversing direction again as it swung away. The demonstration brought home the meaning of the law in a way that no textbook could. "I can understand the traditional way, but I can understand it better if there's more hands-on stuff," said Jake Pursell. "It's the visual." Inman teaches conceptual physics, a hands-on method that relies on concrete examples rather than mathematical formulas. It's an approach that can appeal to younger students, to those who don't have an extensive background in mathematics, or to those who just aren't interested in higher-level physics. Teaching physics to younger students is the basis of a growing movement around the country called "Physics First." Physics First supporters propose reversing the traditional order in which high school science is taught, from biology-chemistry-physics to physics-chemistry-biology. The idea behind physics first, Inman said, is that physics is "the basic science that all other science grows out of. There's physics in biology, but not necessarily biology in physics." At Owen Valley High School, the traditional order of sciences is still in place, but students can take an integrated chemistry/physics course in their freshman year, as well as Physics I -- the course Inman was teaching -- as early as their sophomore year. Indiana's Core 40 graduation requirements include a two-credit biology course; physics, chemistry or integrated chemistry/physics; and another two-credit course. Supporters of Physics First believe the traditional order of teaching is less appropriate than it used to be because of advances in the sciences. For instance, biology used to be largely a descriptive science, but modern biology demands an understanding of the chemical functions of molecules such as DNA. Leon Lederman, a Nobel Prize winner in physics, is one of the foremost advocates of Physics First. He says it's essential for creating a science literate population. "We have to insist that all high school students have some idea of what science is, how it works, what it can do and what it can't do," he has said. The number of students taking physics has been growing since the mid-1980s, according to a 2001 survey of high school physics teachers. Yet two-thirds of high school graduates never take a physics class. The same survey found some enthusiasm for the teaching of conceptual physics, but not much support for Physics First, except among teachers who were already practicing the concept. The American Association of Physics Teachers agrees Physics First has the potential to bring physics to more students and to lay the foundation for advanced science courses. Jean Schick, science coordinator for the Monroe County Community School Corp., says Physics First holds a lot of promise, but there are too many hurdles at this point for MCCSC to support it. One of the biggest obstacles is a lack of teachers. "If you are going to get a degree in physics, unless you have a passion to work with kids, the dollars will drive you in another direction," she said. Bob Sherwood, an IU education professor who is teaching a secondary science methods course this semester, has one student out of 21 who wants to be a physics teacher. "That is not uncommon at universities the size of even Indiana," he said. "Twenty-one secondary science teachers is a bit lower than I expected, but not uncommon because people have to really want to do it and have to be both trained in their science area and learn things to become successful teacher. It's a difficult major, to be honest." Sherwood would like to see high schools offer both freshman and advanced physics so more students will have the chance to study the subject.